The West Ham boss is unsure if the midfielder has a clause in his contract which could pave the way for a return to Old Trafford after his renaissance at Upton Park

West Ham manager Sam Allardyce admits that he would struggle to keep Ravel Morrison at the club ifManchester United wanted to buy back the midfielder.
The 20-year-old, who moved to Upton Park from Old Trafford in January 2012, has made an impressive start to the campaign and received his first England Under-21s cap in the 4-0 win over San Marino on Thursday.
The West Ham boss is unsure whether the Premier League champions have the option to re-sign Morrison and concedes that his side could struggle to keep the midfielder if a substantial offer is received.
"I don't know if there is a buy-back clause and what that figure might be if it even exists," Allardyce told the press.
"But my real big worry is that Manchester United will come back to buy him
.